Introduction

1.1About the ARM PrimeCell PS2 Keyboard/Mouse Interface (PL050)

The PrimeCell PS2 Keyboard/Mouse Interface (KMI) is an Advanced Microcontroller Bus Architecture (AMBA) compliant System-on-a-Chip peripheral that is developed, tested and licensed by ARM.

The PrimeCell KMI is an AMBA slave module, and connects to the Advanced Peripheral Bus (APB). The PrimeCell KMI can be used to implement a keyboard or mouse interface that is IBM PS2 or AT compatible.

Figure 1-1 illustrates the connections to the PrimeCell KMI.

AMBA	AMBA
APB
	APB
	interface
KMIINTR		KMIDATAIN
KMIRXINTR		KMIDATA
KMITXINTR	PrimeCell	nKMIDATAEN
	KMI
	core
KMIREFCLK	logic	KMICLKIN
nKMIRST		KMICLK
SCANMODE		nKMICLKEN
		Open drain
	PrimeCell KMI block	bidirectional
		input/output cells
	Figure 1-1 Connections to the PrimeCell KMI

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© Copyright ARM Limited 1999. All rights reserved.

DDI 0143C

Introduction

1.1.1Features of the PrimeCell KMI

The PrimeCell KMI has the following features:

•compliance to the AMBA Specification (Rev 2.0) onwards for easy integration into System-on-a-Chip (SoC) implementation

•IBM PS2 or AT-compatible keyboard or mouse interface

•half-duplex bidirectional synchronous serial interface using open-drain outputs for clock and data

•programmable 4-bit reference clock divider

•operation in polled or interrupt-driven mode

•separately maskable transmit and receive interrupts

•single combined interrupt output

•odd parity generation and checking

•register bits for override of keyboard clock and data lines.

Additional test registers and modes are implemented for functional verification and manufacturing test.

DDI 0143C

© Copyright ARM Limited 1999. All rights reserved.

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